June 20, 2013

Post: More on MySQL transaction descriptors optimization

April 26, 2013 By Leave a Comment

…QPI bandwidth, and the third one features even higher QPI speed (and thus, faster inter-process/node communication). Results: First …requests=0 –percentile=99 –mysql-user=root –mysql-db=sbtest8t1M –mysql-table-engine=INNODB –mysql-socket=/tmp/mysql.sock –oltp-point-selects=1 –oltp-simple-…

Filed Under: Benchmarks, MySQL Tagged With: ,

Comment: MySQL Partitioning - can save you or kill you

April 30, 2013 By 45 Comments

… (within a single connection) anywhere in any ‘free’ variant of MySQL. PARTITIONs are scanned one at a time. (Please provide specific….) I would argue that single-row queries (SELECT, INSERT, DELETE, UPDATE) are similar in speed between PARTITIONed or non-PARTITIONed. When PARTITIONed… PARTITIONing. I go into more details (and code) here: http://mysql.rjweb.org/doc.php/partitionmaint The third use case for…

Filed Under: Insight for DBAs, MySQL Tagged With: , ,

Post: How fast can MySQL Process Data

April 9, 2008 By 3 Comments

…=MEMORY DEFAULT CHARSET=latin1 mysql> select count(*) from m; +———-+ | count(*) | +———-+ | 1047684 | +———-+ 1 row in set (0.00 sec) mysql> select count(*) from m where…) the filtering speed stays about the same: mysql> select count(*) from m3; +———-+ | count(*) | +———-+ | 10476840 | +———-+ 1 row in set (0.00 sec) mysql> select count(*) from…

Filed Under: Benchmarks Tagged With:

Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark

March 11, 2013 By 7 Comments

… disk problem, I pointed the MySQL 5.6.10 at the MySQL 5.5.30 data directory.  Tthe speed was essentially the same… pool in pages afterwards: mysql> select sq.*, pages / (@@innodb_buffer_pool_size / 16384) * 100 pct_buffer_pool from ( select table_name, index_name… set (0.00 sec) mysql> select sq.*, pages / ((@@innodb_buffer_pool_size / 16384)) * 100 pct_buffer_pool from ( select table_name, index_name…

Filed Under: MySQL Tagged With: , , , , ,

Post: UDF -vs- MySQL Stored Function

September 6, 2010 By 8 Comments

…: mysql> select ltrim_junk_mysql(author), ltrim_junk_mysql(title) from paintings limit 100000; 100000 rows in set (2.97 sec) mysql> select remove_dups_mysql(author… using available functions. With that speed I could even scan the whole table of 7 million records: mysql> select count(*) from paintings where…

Filed Under: MySQL Tagged With: , ,

Post: Why MySQL could be slow with large tables ?

June 9, 2006 By 141 Comments

…by index: mysql> select count(pad) from large; +————+ | count(pad) | +————+ | 31457280 | +————+ 1 row in set (4 min 58.63 sec) mysql> select count(pad…in random places – this may affect index scan/range scan speed dramatically. The rows referenced by indexes also could be …

Filed Under: Insight for DBAs Tagged With: ,

Post: How fast can you sort data with MySQL ?

August 18, 2007 By 26 Comments

… sort_buffer_size is 32K which gives us the following speed: mysql> select * from gt order by i desc limit 10; +——–+——————————————+ | i | c… large sort_buffer_size ? mysql> set sort_buffer_size=100000000; Query OK, 0 rows affected (0.00 sec) mysql> select * from gt order…

Filed Under: Benchmarks, Insight for DBAs Tagged With:

Post: InnoDB Full-text Search in MySQL 5.6: Part 2, The Queries!

March 4, 2013 By 7 Comments

… ft_min_word_length. First, MyISAM, with MySQL 5.5, on the SEO data set: mysql: SELECT id, title, MATCH(title, body) AGAINST… | +——+———————————————————————–+——————–+ The same query, run against InnoDB on 5.6.10: mysql: SELECT id, title, MATCH(title, body) AGAINST (‘arizona business records’ IN…, we will take a look at performance. How does the speed of InnoDB FTS compare to its MyISAM counterpart, and what…

Filed Under: Insight for DBAs, Insight for Developers, MySQL Tagged With: , , , , ,

Post: Using any general purpose computer as a special purpose SIMD computer

May 16, 2011 By 5 Comments

… the serial version as run by the native database interface (MySQL): mysql> select word, md5(word), md5(reverse(word)), count(*) from words2 group… set (5.00 sec) Since the data fits in memory speed is near constant and the single threaded operation burns one…. Likely current network technologies can not support such a degree. mysql> select min(id),max(id) from words; +———+———+ | min(id) | max(id…

Filed Under: MySQL

Post: Testing MySQL column stores

August 16, 2010 By 15 Comments

…, including: Ease of installation Loading capability and speed of loading Accuracy of results of queries… queries. ICE supports almost all of the MySQL aggregation functions. Notably, GROUP_CONCAT is not … queries on InfiniDB. In particular the query “select count(*) from carsales.sales_fact” when run…

Filed Under: MySQL
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